1973 enlargement of the European Communities

Part of a series of articles on
UK membership of the European Union (1973–2020)
Accession Treaty of Accession 1972 1972 EC Act 1973 enlargement of the EC
1975 referendum Referendum Act (results)
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The 1973 enlargement of the European Communities was the first enlargement of the European Communities (EC), now the European Union (EU). Denmark, Ireland and the United Kingdom (UK) acceded to the EC on 1 January 1973. Gibraltar and Greenland also joined the EC as part of the United Kingdom and Denmark respectively, but the Danish Faroe Islands, the other British Overseas Territories and the Crown dependencies of the United Kingdom did not join the EC.

Ireland and Denmark both held referendums in 1972 in May and October respectively, and the United Kingdom held a referendum in 1975, on membership of the EC, all which approved membership of the EC. Norway planned to accede, but this was rejected in a referendum held in September 1972. In 1992 Norway again applied to join, but voters again rejected the proposal in a 1994 referendum.

Greenland later withdrew from the EC on 1 January 1985 after a referendum in 1982. This was followed by the United Kingdom holding a referendum in 2016 on membership which resulted in the United Kingdom voting to leave the EU.